Employee Benefits (Details 5) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	$ 18,281	$ 18,166
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pooled separate accounts
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Inputs (Level 2) | Pooled separate accounts
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	18,281	18,166
Inputs (Level 3) | Pooled separate accounts
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	$ 0	$ 0